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/*
* EIM driver for Freescale's i.MX chips
*
* Copyright (C) 2013 Freescale Semiconductor, Inc.
*
* This file is licensed under the terms of the GNU General Public
* License version 2. This program is licensed "as is" without any
* warranty of any kind, whether express or implied.
*/
#include <linux/module.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/of_device.h>
static const struct of_device_id weim_id_table[] = {
{ .compatible = "fsl,imx6q-weim", },
{}
};
MODULE_DEVICE_TABLE(of, weim_id_table);
#define CS_TIMING_LEN 6
#define CS_REG_RANGE 0x18
/* Parse and set the timing for this device. */
static int weim_timing_setup(struct device_node *np, void __iomem *base)
{
u32 value[CS_TIMING_LEN];
u32 cs_idx;
int ret;
int i;
/* get the CS index from this child node's "reg" property. */
ret = of_property_read_u32(np, "reg", &cs_idx);
if (ret)
return ret;
/* The weim has four chip selects. */
if (cs_idx > 3)
return -EINVAL;
ret = of_property_read_u32_array(np, "fsl,weim-cs-timing",
value, CS_TIMING_LEN);
if (ret)
return ret;
/* set the timing for WEIM */
for (i = 0; i < CS_TIMING_LEN; i++)
writel(value[i], base + cs_idx * CS_REG_RANGE + i * 4);
return 0;
}
static int weim_parse_dt(struct platform_device *pdev, void __iomem *base)
{
struct device_node *child;
int ret;
for_each_child_of_node(pdev->dev.of_node, child) {
if (!child->name)
continue;
ret = weim_timing_setup(child, base);
if (ret) {
dev_err(&pdev->dev, "%s set timing failed.\n",
child->full_name);
return ret;
}
}
ret = of_platform_populate(pdev->dev.of_node, NULL, NULL, &pdev->dev);
if (ret)
dev_err(&pdev->dev, "%s fail to create devices.\n",
pdev->dev.of_node->full_name);
return ret;
}
static int weim_probe(struct platform_device *pdev)
{
struct resource *res;
struct clk *clk;
void __iomem *base;
int ret = -EINVAL;
/* get the resource */
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
base = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(base)) {
ret = PTR_ERR(base);
goto weim_err;
}
/* get the clock */
clk = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(clk))
goto weim_err;
ret = clk_prepare_enable(clk);
if (ret)
goto weim_err;
/* parse the device node */
ret = weim_parse_dt(pdev, base);
if (ret) {
clk_disable_unprepare(clk);
goto weim_err;
}
dev_info(&pdev->dev, "WEIM driver registered.\n");
return 0;
weim_err:
return ret;
}
static struct platform_driver weim_driver = {
.driver = {
.name = "imx-weim",
.of_match_table = weim_id_table,
},
.probe = weim_probe,
};
module_platform_driver(weim_driver);
MODULE_AUTHOR("Freescale Semiconductor Inc.");
MODULE_DESCRIPTION("i.MX EIM Controller Driver");
MODULE_LICENSE("GPL");
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